High-torque pneumatic-type rotary timer



June 10, 1969 w. T. WEISMANN 3,448,833

HIGH-TORQUE PNEUMATIC-TYPE ROTARY TIMER Filed Dec. 12, 1967 Sheet 'of 2INVENTOR. WALTER T WEISMANN BY Flg. 4 34 WW TOR NEYS June 10, 1969 w. T.WEISMANN 3,448,833

HIGH-TORQUE PNEUMATIC-TYPE ROTARY TIMER Filed Dec. 12, 1967 Sheet 2 of 2j 2 ag F|g.6

w //m 36 26 32 n HIGH-TORQUE TIMED Q POWER 26|\2B POWER SOURCE OUTPUTIZA" 3 INVENTOR.

7 WALTER T WEISMANN BYH m 3411 3| ATTORNEYS United States Patent3,448,833 HIGH-TORQUE PNEUMATIC-TYPE ROTARY TIMER Walter T. Weismann,Hackettstown, N.J., assignor to the United States of America asrepresented by the Secretary of the Army Filed Dec. 12, 1967, Ser. No.690,029 Int. Cl. F16d 57/00 US. Cl. 188-91 2 Claims ABSTRACT OF THEDISCLOSURE A rotary timer wherein pneumatic escapement at high torquelevels is provided. Two coaxial diametrically-opposed air cylinders aremounted on complementary crank case housing blocks which jointly providea sealed crank case chamber between the cylinders. A pair of opposedpistons, one in each cylinder, are connected with a central common crankshaft, each by a two-part connecting rod, the piston ends of which arecoaxial with the pistons and the crank shaft ends of which are offset.An air manifold connects the outer ends of the cylinders to permit airflow from one to the other as a closed system, in response to pistonmovement 'as the crank shaft is driven by a torque-producing device orrotary power source to be time controlled. A rotary valve in themanifold connection may be set full open or partially closed to anydesired degree to set the timing rate of the timer. This varies therestriction or resistance to air flow through the manifold and thus therate at which the timing crank shaft may be rotated with applied torquefrom the controlled device or power source.

The invention described herein may be manufactured, used, and licensedby or for the Government for governmental purposes without the paymentto me of any royalty thereon.

The present invention relates to mechanical escapement rotary timers,and has for an object to provide a more rugged timer of that type forcontrolling angular velocity over a relatively-wide speed range atrelatively-high torque levels. It has been found that by resorting topnematic escapement control in timing devices numerousadvantages may begained over the basic mechanical escapement as found in watches, clocksand conventional timing devices. Greater immunity from shock, vibration,spin and setback forces can be attained. With a pneumatic escapement, agreater amount of mechanical energy can be absorbed without the use oflarge gear trains. The conventional method for controlling the angularvelocity of the timing movement, as in a watch, by a hair-springadjustment, provides a limited speed or variation range and thestructural elements involved are relatively fragile.

A pneumatic type escapement timer in accodance with the invention,however, is adapted for use where:

(a) Angular velocity or rotational speed must be controlled atrelatively high torque levels,

(b) A relatively wide range of speed adjustment is required', and

(c) A conventional mechanical escapement is not rugged enough to meetenvironmental operating conditions.

In accordance with a present preferred form of the invention, ahigh-torque pneumatic-type rotary timer is provided in a closed systemthat can be hermetically sealed so that no outside 'air or gaseous fluidis required for the continuous operation thereof. A pair of doubleactingpistons and cylnders are arranged in coaxial diametrically-oppositerelation to each other about a central crank shaft to which the pistonsare connected. The crank "Ice shaft extends outwardly at one end from adivided blocktype crank case of relatively large mass for connectionwith any torque-producing power source or device which requireshigh-torque timing control.

The piston connecting rods are of a two-piece welded construction morereadily to provide an off-set driving connection with the crank shaft.When driving torque is applied to the crank shaft the pistons are movedin unison by the shaft rotation on alternate compression and intakestrokes. A manifold or conduit connection is provided between the outerend of the cylnders to permit a flow therebetween to equalize thepressure between the cylinders as the pistons move on the compression orexhaust stroke in the one and the decompression or intake stroke in theother. The inner ends of the cylinders are more closely andsubstantially-directly connected 'by the sealed crank case which thusprovides for air flow and pressure equalization therein as the pistonsmove.

A rotary valve in the manifold or conduit connection acts as a variableimpedance element for restricting the air flow from one cylinder to theother to 'any desired degree and thereby loading the crank shaft toprovide timing control in a corresponding degree. A heavy driving torquecan thus be controlled and the timed release of the driving force can beset over a relatively wide speed range.

The invention will, however, be further understood from the followingdescription of a present preferred embodiment thereof when consideredwith reference to the accompanying drawings.

In the drawings,

FIG. 1 is frontal View, in perspective, of a high-torque pneumatic-typerotary timer embodying the invention,

FIGS. 2 and 3 are similar views of two related and complementary partsof the timer of FIG. 1, showing further details of construction inaccordance with the invention,

FIG. 4 is a further view, in perspective, of an assembly group ofelements of the timer of FIG. 1, also showing additional details thereofin accordance with the invention,

FIG. 5 is an enlarged cross-sectional view of the timer as in FIG. 1,taken on the section line 5--5 thereof, to show the construction andoperative relation of the in-- terior elements in accordance with theinvention,

FIG. 6 is a fragmentary cross-sectional view, of a portion of the timeras in FIG. 5, showing a change in the position of a control elementthereof for operation in accordance with the invention, and

FIG. 7 is a top view of the timer as in FIG. 1 in operative relation toa power source for timing control thereof in accordance with theinvention.

Referring to the drawings, wherein like reference nuerals are used todesignate like elements throughout the various figures, and referringparticularly to FIGS. 1-3 inclusive, a central relatively-massive crankcase housing 12 carries two diametrically opposed cylinders 10 and 11which are mounted on complementary crank-case housing blocks 12A and 12Brespectively. The latter are of rectangular construction with a centralgrooved recess 14 in each face thereof as shown in FIGS. 2 and 3, whichunite to form a centrally-located crank-case chamber 15 between themwithin the housing 12 as shown in FIG. 5. to which attention is nowdirected along with FIGS. 1-3.

'Iwo opposed pistons 16 and 17 in the cylinders 10 and 11, respectively,are connected with a central rotary transversely-extending crank shaft18 by coaxial connecting rods 19 and connecting rod extensions 20therefor on opposite sides of the common piston and cylinder axis asindicated. The connecting rods 19 are connected with the respectivepistons by wrist pins indicated at 21 and are joined to the extensions20 by any suitable means 3 such as elongated joints or welds 22 as shownin FIG. 5.

The crank shaft is provided with an intermediate crank pin sectioncomprising two-spaced crank arms 24 and a connecting crank pin 23,between inner and outer shaft sections, which are journaled in endbearings or hearing plates 26 and 27, respectively. The latter aremounted on opposite faces of the assembled crank case housing. Acircular-spacing block or washer for the connectingrod ends of theextensions 20 is provided on the crank pin 23. The bearing plates serveto hold the housing blocks in tight closed relation and may be attachedthereto by any suitable means, such as four mounting screws 28 (FIG. 1).The forward section of the crank shaft extends outwardly of the bearingplate 27 and the crank case housing 12, as indicated at 18A, forconnection with any torque-producing device or rotary power source to betime controlled, as will hereinafter be described.

It will be seen that the crank case chamber .15 is completely closed orsealed between the housing blocks 12A and 12B and covered by the bearingplates 26 and 27. The crank case may thus be partly filled withlubricant and completely sealed. The air therein is subject to free flowbetween the inner cylinder ends to equalize the pressure changes thereincaused by the reciprocating piston movement.

At the outer ends of the cylinders the pressure changes caused by thepiston movement are equalized through external connecting and timingcontrol means of unitary construction. This is further shown in FIG. 4as it appears before mounting on the cylinder and crank case housing,and in FIGS. 6 and 7 to which attention is also directed. It comprises atubular air manifold 30* having two conduit arms 31 and 32 with acentral valve casing 29 therebetween. The valve casing is mounted on andmay be integral with, the rear bearing plate 26 to extend axially andrearwardly of the crank case housing 12, also as shown in FIGS. 1 and 5.

The free ends of the manifold or conduit arms 31 and 32 are terminatedin cylinder heads 33 and 34 respectively for the cylinders 10 and 11 andare in communication with the outer ends thereof through a slottedopening 35 on the inner face of each cylinder head. The cylinder headsare attached to the cylinders by any suitable means such as screws 36 asindicated in FIG. 1. These and other screws, such as 28, are omitted inFIG. 5 to aid in clarifying the showing of other structural elements.

The valve casing 29 is provided with a rotary valve element 39 betweenthe ends of the conduit arms 31 and 32 therein as shown in FIGS. 5 and6. The valve element is provided with a transverse opening 40 which canbe turned into the open position in alignment with the conduit arms, asin FIG. 6, to permit full fluid flow therethrough or turned, as in FIG.5, to partially close and restrict the fluid flow therethrough as a loadon the piston elements 10 and 11. A manual control knob 41 is connectedwith the valve element 39, as outlined in FIGS. 5 and 6 and shown inFIGS. 1, 4 and 7, to set the valve open to various degrees for timingcontrol. Thus the control knob may be graduated or provided with agraduated scale 42 and a fixed indicator or pointer means 43- therefor,FIG. 7, to aid in setting the valve as above. In FIGS. 1 and 7, thescale 42 is shown with the knob 41 adjusted for the full open positionof the valve, as in FIG. 6.

" As shown in FIG. 7, the timing control shaft 18, that is, the outerend 18A, may be connected to apply timing control to a rotary shaft,such as a shaft 44, which operates to apply a high degree of torque. Itmay be a driven electric generator shaft in connection with a powersource or it may, as here, be the shaft of a high-torque power source45, the opposite end of which provides a driving torque for any usefulpurpose at a fixed speed. In order to operate the timing control meansat a relatively low speed in connection with a higher-speed hightorquedevice at 45, the shafts 18A and 44 may be connected by suitablegearing, such as a small pinion driving gear 46 on the shaft 44 and alarger driven gear 47 on the shaft 18A.

What is claimed is:

1. A pneumatic high-torque variable-speed rotary timer, adapted forimmunity from shock, vibration, spin and setback forces, comprising incombination,

a pair of complementary rectangular crank-case housing blocks ofrelatively-large mass with a central grooved recess in each face thereofjointly providing a crank case with an inner crank-case chamber,

a pair of diametrically-opposed cylinders mounted on said crank case onein connection with each of said housing blocks and communicating withsaid chamber at their inner ends,

a central crank shaft extending transversely through said chamber,

opposed coaxially-aligned pistons one in each of said cylindersconnected with said crank shaft each by a two-part connecting rod thepiston end of which is coaxial with the piston and the crank-shaft endof which is offset therefrom,

fluid-conduit type manifold means connecting the outer ends of thecylinders to permit fluid flow from one to the other in response topiston movement,

rotary valve means for said manifold means adapted to be set full-openor partially-closed to any desired degree and connected therein to varythe restriction and resistance to fluid flow therethrough for applyinghigh-torque timing control to devices connected with said crank shaft,said rotary valve means including a valve casing providing a gearbearing for the crank shaft and closure means for the rear of the crankcase,

whereby the angular velocity of the crank shaft over a relatively widespeed range can be controlled thereby at relatively high-torque levels,and

manual adjustment means including a graduated dial for setting saidvalve means to control the timing rate of said timer.

2. A pneumatic high-torque variable-speed rotary timer as defined inclaim .1, wherein the cylinders are closed at the outer ends bydetachable cylinder heads carried by the ends of the manifold means andforming a unitary part thereof and the manifold means further includestwo thin-walled pipe-like conduit arms connected one between said valvecasing and each of said cylinder heads.

References Cited UNITED STATES PATENTS 1,630,711 5/1927 McCleary l8'8911,907,017 5/1933- Turman l889l X 3,026,974 3/1962 Gouker l8891 GEORGE E.A. HALVOSA, Primary Examiner.

